Arm restraint system for harness mounting

ABSTRACT

A harness mounted arm restraint system for the occupant of an aircraft  ejion seat to prevent the arms from flailing and being injured during ejection. Harness-mounted ribbons with slidable rings on them are hooked to snubber lines. The snubber lines are secured to the airframe of the aircraft so that when the seat ejects, the snubber lines pull the ribbons tightly around the upper arms and forearms of the seated occupant. The snubber lines then break away from the frame but the lines and ribbons are kept taut by a snubber block on the seat. The snubber lines are cut when seat and occupant separate.

STATEMENT OF GOVERNMENT INTEREST

The invention described herein may be manufactured and used by or forthe Government of the United States of America for governmental purposeswithout the payment of any royalties thereon or therefor.

BACKGROUND OF THE INVENTION

The present invention relates to an arm restraint system for anoccupant, such as an aircrewman, of an aircraft ejection seat, and moreparticularly to a system, suitable for harness mounting, for restrainingthe arms against the body during the ejection to prevent the arms fromflailing and becoming injured.

Arm flail injury is one of the most common major injuries resulting fromhigh speed ejection. The windblast that strikes the crewman can twistand bend his arms, causing fractures and dislocations.

Various prior art devices attempted to reduce these injuries byrestraining the arms. However, they often do not adequately restrain thearms, or usually require substantial modification to the ejection seat.Some of these devices also require too much space for operation.

SUMMARY OF THE INVENTION

It is therefore an object of the invention to keep arms restrainedagainst the body of a crewman ejecting from an aircraft to preventinjury due to flailing arms.

A further object of the invention is to provide an arm restrainingsystem requiring minimal modification to the seat.

It is also an object to provide a simple and inexpensive restrainingsystem that does not require much space.

Still another object of the invention is to provide a seat ejectionsystem which deploys quickly.

Briefly, these and other objects and features of the invention areaccomplished by a pair of ribbons fixed at their one ends to theparachute harness at either side midway between the occupant's waist andshoulders and at their other ends to the back of the harness at eitherside near the occupant's femur socket joints. The ribbons route throughrings fixed to the harness near each of the occupant's pectoral muscles.When the seat ejects, a pair of snubber lines, each releasably fixed atone end to the floor of the aircraft and each slidably hooked at theother end to the ribbons near the pectoral muscles, pull ribbonsdownwardly and inwardly, tightening them about the occupant's upper armsand forearms. A snubber block connected to the lines keeps the ribbonstaut after ejection and a cutter cuts them when the occupant and seatseparate.

DESCRIPTION OF THE DRAWINGS

Other objects, advantages and novel features of the invention willbecome apparent from the following detailed description of the inventionwhen considered in conjunction with the accompanying drawings wherein:

FIG. 1 is a front view of an arm restraint system according to theinvention as worn by a crewman secured in an aircraft ejection seat;

FIG. 2 is a side view of the arm restraint system according to theinvention;

FIG. 3 is an enlarged fragmentary view of the arm restraint system ofFIG. 1 near the shoulder; and

FIG. 4 is a perspective view of the arm restraint system fully deployed.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to the drawings wherein like characters designate like orcorresponding parts throughout the several views, there is shown in FIG.1 a crewman in an aircraft ejection seat 12 wearing a conventionalparachute harness 10. In the event of an emergency requiring egress ofthe crewman during flight, ejection is initiated by a hand-operated pullring 14 positioned on the seat 12 between the thighs of the crewman.

The arm restraint system of the present invention includes two connectorassemblies 15a and 15b sewn to the front of parachute harness 10 belowthe right and left pectoral muscles, respectively; two breakaway loops18a and 18b, such as Velcro, sewn to the right and left sleeves,respectively, of the crewman's outer garment near the shoulders; and twobreakaway loops 20a (FIG. 2) and 20b (not shown) sewn to the back ofharness 10 over the right and left shoulder blades, respectively.

As shown in FIG. 3, assembly 15a includes a slidable ring 24a whichrests on top of a ring 16a, and is held in place by a breakaway loop26a. Assembly 15b similarly includes rings 16b and 24b and loop 26b (notshown). Ribbons 22a and 22b, each sewn at one end to harness 10 midwaybetween the waist and the shoulders on the sides of the torso, routeupwardly through their respective loops 20a and 20b, loops 18a and 18b,and rings 16a and 16b. Ribbons 22a and 22b then route back through loops18a and 18b and loops 20a and 20b, terminating at the back of harness 10at the right and left femur socket joints, respectively.

Snubber lines 28a and 28b are each hooked at one end to rings 24a and24b, respectively, by snap-on fasteners 30a (FIG. 3) and 30b (not shown)and run downwardly through a snubber block 32 and a cutter 36 locatedbetween the crewman's legs and attached to the seat 12. The other endsof snubber lines 28a and 28b are secured to airframe 34 of the aircraftby breakaway rivets 38. Snubber block 32 is configured to permit lines28a and 28b to slide downwardly therethrough but prevents upwardmovement, with cutter 36 severing lines 28a and 28b when seat/manseparation is activated.

In operation, the aircrewman initiates ejection by pulling pull ring 14.This places his hands in the best entrapment position, althoughentrapment will also occur if the hands are on the thighs or on theflight control stick. As the seat 12 moves up the rails (not shown), thesnubber lines 28a and 28b move down through the snubber block 32,pulling the slidable rings 24a and 24b free of breakaway loops 26a and26b, respectively, and towards snubber block 32. Ribbons 22a and 22bdetach from loops 18a, 20a, and 18b, 20b, respectively, and become taut.The arms may be restrained before seat ejection, if desired, by locatinga retracting motor below snubber block 32 to pull snubber lines 28a and28b down through snubber block 32. The upper portions of ribbons 22a and22b route over the upper arms and through rings 16a and 16b,respectively, holding the upper arms against the torso. The lower partsof ribbons 22a and 22b extend from the femur socket joints over theforearms to the slidable rings 24a and 24b, holding the forearms againstthe thighs as the crewman enters the airstream.

When the force of the seat 12 ejecting reaches a specified level, rivets38 break. Ribbons 22a and 22b and snubber lines 28a and 28b remain tautbecause the snubber block 32 holds the snubber lines 28a and 28b inplace. Cutter 36 subsequently cuts the snubber lines 28a and 28b at thetime of seat/man separation.

Some of the many features and advantages of the invention should now bereadily apparent. For instance, the system secures the arms against thetorso, deploying immediately upon ejection. Minimal modification to theseat is required. The system requires only enough space for the ribbons,the snubber lines, and the snubber block. It is also a simple andrelatively inexpensive system.

Having thus described the invention, it will be apparent to thoseskilled in the art that various modifications can be made within thespirit and scope of the present invention. Accordingly, it is intendedto encompass all such modifications.

What is claimed is:
 1. An arm restraint system for an aircraft ejectionseat occupant wearing a parachute harness, comprising:a pair of ribbonsattachable at their one ends to the harness at either side between theoccupant's waist and shoulders and at their other ends to the back ofthe harness at either side over the occupant's femur socket joints;securing means attachable to the harness for slidably routing each ofsaid ribbons behind the occupant's arms and over the pectoral muscles;and deploying means operatively connected to said ribbons for pullingand keeping said ribbons taut about the occupant's upper arms andforearms during seat ejection, said deploying means automaticallydisengaging upon separation of the occupant from the seat.
 2. An armrestraint system in claim 1 wherein said securing means furthercomprises:a pair of rings attachable to the front of the harness ateither side over the pectoral muscles for receiving respective ones ofsaid ribbons; and a pair of back breakaway loops attachable to the backof the harness at either side over the shoulder blades for releasablyreceiving respective ones of said ribbons.
 3. An arm restraint system asin claim 1 wherein said deploying means comprises:a pair of snubberlines slidably connected at their one ends to respective ones of saidribbons along their lengths between the pectoral muscles and said otherends of said ribbons, adjacent to the pectoral muscles, and releasablyconnectable at their other ends to the aircraft between the occupant'slegs; gripping means positioned between the occupant's legs andoperatively connected to said lines for preventing release of anytension applied to said lines upon ejection; and cutter meansoperatively connected to said lines for severing said lines uponseparation of the occupant from the seat.
 4. An arm restraint system foran aircraft ejection seat occupant wearing a parachute harness,comprising:a pair of rings formed to be fixed to the front of theharness at either side below the occupant's pectoral muscles; a pair ofback breakaway loops formed to be fixed to the back of the harness ateither side adjacent to the occupant's shoulder blades; a pair ofribbons formed to be fixed at their one ends to the harness at eitherside midway between the occupant's waist and shoulders, each of saidribbons routing from said one end through respective ones of said backbreakaway loops, rings and back through said back breakaway loops, theirother ends terminating at and formed to be fixed to the back of theharness at either side adjacent to the occupant's femur socket joints; apair of snubber lines slidably connected at their one ends to respectiveones of said ribbons along their lengths between said rings and saidother ends of said ribbons, adjacent to said rings, and formed to bereleasably connected at their other ends to the aircraft between theoccupant's legs; gripping means formed to be connected to the seatbetween the occupant's legs and operatively connected to said lines forpreventing release of any tension applied to said lines upon seatejection; and cutter means formed to be connected to the seat andoperatively connected to said lines for severing said lines uponseparation of the occupant from the seat.
 5. An arm restraint system asin claim 4 further comprising:a pair of side breakaway loops, one on theoutside of each of the occupant's arms below the shoulder, for routingrespective ones of said ribbons therethrough.
 6. An arm restraint systemas in claim 5 further comprising:a pair of front breakaway loops, eachattachable to the front of the harness near respective ones of saidrings, Ior releasably securing said one ends of said snubber lines.